MC Grating software of a diffraction grating analysis and design that would run on a PC was developed from 1999 by Dr. Nikolai Lyndin senior physicist of General Physics Institute, Moscow, lyndin@ran.gpi.ru. For many years the author is involved with solving scientific and practical problems of using multilayer grating structures in grating couplers, biochemistry sensors, laser resonator modes selection and others. For this reason from the beginning this grating software was designed for personal use to insure a maximum convenience for the user.
Initially the grating software included C-method^1-4 based codes that are very appropriate for smooth grating profile analysis. In 2003 the grating software was extended with True Modes Method^5-9 (TMM) and from 2007 with Fourier Modes Method^10-12 (FMM). The modal methods codes are naturally adapted for the lamellar gratings and are complementary to the C-method based codes. Reliable lamellar modes searching algorithm in TMM and suppression of the FMM instabilities in highly conductive gratings¹² were developed and implemented.
From 2008 Crossed-Grating software is available. 

MC Grating software package is designed to run on any Windows® OS. The interface is written in Delphi while the most critical matrix routines are taken from Lapack 3.1.1 package and rewritten in C++. The Lapack routines DLL is optimized for Intel processors and provides calculation speed close to the speed of original Intel® Math Kernel Library (Intel® MKL) routines. MC Grating codes are hardware protected with a HASP HL USB dongle.

Generally the grating software is intended to calculate the diffraction efficiencies (power) and complex amplitude (module, phase or real, imagine part) of diffracted waves in superstrate (cover) and substrate under incidence of a plane wave from the cover. Also a complex field and power flow components in the structure and ambient medium can be calculated. If the structure hasn't a grating region at all the software considers this structure as a simple multilayer stack that has only reflected and transmitted waves (zero diffraction orders) and the calculations became very fast.

A search of incident plane wave resonance with a waveguide mode supported by the multilayer grating structure is available. This function includes search of double resonances in two different diffraction orders. The search results are effective refractive indexes of structure modes, resonance positions, resonance width and associated with the resonance poles parameters¹³ in a complex plane with the wave vector projection on a grating and radiation coefficient as a coordinates. Poles parameters are accessible trough an "Analysis" window.

The Analysis option is intended to investigate a finite incident Gaussian beam reflection and transmission. Calculation is based on two different approaches: Fast Fourier transform of diffraction efficiencies angular scan or the poles approach if in advance a resonance search was fulfilled.

The multidimensional optimization method is based on the approach suggested by Davidon (1959), and further developed by Fletcher and Powell. The Davidon - Fletcher - Powell method¹⁴ is a Quasi-Newton Method also known as a Variable Metrics Method. Almost every incident wave, and structure parameters, including refractive indexes, can be set as variables. There isn't any restriction on optimization search area except a physical meaning of the variable parameters (for example a layer thickness can not be negative). Several methods of a criterion function construction allow solving variety of design and inverse structure reconstruction problems.

In addition the Modal methods based codes include option to analyze the TMM or FMM modes (effective indexes and field distribution) in every layer including cross coupling and scattering matrix coefficients.

The Main material catalog contains dispersion data of many dielectric, metal and semiconductor materials. For the user convenience a frequently used materials can be copied into a custom catalog. The user can edit any material in this catalog or add any new material.

All codes have almost the same interface adapted for particular code possibilities including Crossed-Grating package. The main form is a container for independent project editor windows. Editor window may display a text with a structure parameters or a text table with results of calculation. The graphic tools take data from the results text table. This seems to be reasonable because the user has an opportunity to edit the data and display in a graphic form a saved data files. The user can change the results precision and diffraction orders of interest displayed in the text table without repeating calculation because a complete result data is kept in a PC memory. The structure parameters can be edited as from the text window or from dialog window "Settings". Dialog windows are also used to access any other options.

The MC Grating software were successfully used for designing biosensors^15,16, selective ordinary¹⁷ and grating¹⁸ mirrors and broadband reflective gratings¹⁹ for laser pulse compression.

The MC Grating software demo version has only one restriction: it sets all refractive indexes multiple to 0.5. For this reason a material catalog can be used only as a reference and refractive indexes can not be set as a variable parameters in optimization procedure. Nevertheless the demo version remains enough flexibility to serve for education and training needs.

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3. Lifeng Li, “Multilayer-coated diffraction gratings: differential method of Chandezon et al. revisited”, J. Opt. Soc. Am. 11, 2816-2828 (1994)
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8. Lifeng Li, “A modal analysis of lamella diffraction gratings in conical mountings”, Journal of Modern Optics, 40, 553-573 (1993)
9. M. Foresti, L. Menez, A. V. Tishchenko, "Modal method in deep metal-dielectric gratings: the decisive role of hidden modes", J. Opt. Soc. Am. A, Vol. 23, No. 10, p. 2501 (2006)
10. P. Lalanne and G. M. Morris, "Highly improved convergence of the coupled-wave method for TM polarization", J. Opt. Soc. Am. A, Vol. 13, No. 4, p. 779 (1996) 
11. Lifeng Li, "Use of Fourier series in the analysis of discontinuous periodic structures", J. Opt. Soc. Am. A, Vol 13, No. 9, p. 1870 (1996)
12. N. Lyndin, O. Parriaux and A.V. Tishchenko, "Modal analysis and suppression of the FMM instabilities in highly conductive gratings", J. Opt. Soc. Am. A, to be published
13. S. M. Loktev, N. M. Lyndin, O. Parriaux, V. A. Sychugov, A. V. Tishchenko, “Reflection of a finite light beam from a finite waveguide grating”, Sov. J. Quantum Electron. 27 445-449 (1997)
14. Fletcher, R., Powell, M.J.D., Computer Journal, 6, 163.1 (1963)
15. N. M. Lyndin, V. A. Sychugov, A. V. Tishchenko, B. A. Usievich, “Analytical methods and apparatus employing an optical sensor device with refractive index modulation”, US Patent 6,218,194 April 17, 2001
16. N. M. Lyndin, “Optical grating structures and method for their manufacture”, PCT Patent WO/2002/082130 October 17, 2002
17. V A Sychugov, V A Mikhailov, V A Kondratyuk, N M Lyndin, J Frahm, A I Zagumennyi, Yu D Zavartsev, P A Studenikin, “Short-wavelength (λ = 914 nm) microlaser operating on an Nd3+:YVO4 crystal”, QUANTUM ELECTRON, 30 (1), 13-14 (2000)
18. N. Destouches, J.-C. Pommier, O. Parriaux, T. Clausnitzer, N. Lyndin, S. Tonchev,“Narrow band resonant grating of 100% reflection under normal incidence”, Optics Express, 14(26), 12613-12622 (2006)
19. A. Trisorio, M. Flury, N. Lyndin, A.V. Tishchenko and S. Tonchev, “Réseaux résonnants pour la compression d'impulsions laser femtosecondes”, J. Phys. IV France 127, 87-90 (2005)